Reservoir sedimentology of the M. Triassic Halfway Fm. , Wembley field, Alberta

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:7079428

Willis, A J ^[1]

---

1. Univ. of Alberta, Edmonton (Canada)

The Middle Triassic Halfway Formation of west-central Alberta is interpreted as a prograding barrier island shoreline deposit. A detailed sedimentological study based on 130 cored sequences and 300 well logs in the Wembley area (Townships 72-73, Ranges 7-9, West of Sixth Meridian) has enabled the author to delineate the geometry of reservoir units, interpreted as tidal inlet fill, upper shoreface, and flood-tidal delta sandstones. Complete shoreface sequences average 15 m in thickness and form mappable trends tens of kilometers along depositional strike, but are only continuous for a few kilometers across dip, with the intervening areas having been reworked by one or more migrating tidal inlets. The strike-elongate inlet-fill sequences cover more than 50% of the field area. They are typically 10 m thick and exhibit the best porosities due to leaching of bioclastic material in the lower part of the fill, but the down-cutting of successive inlets makes the reservoir sands laterally discontinuous. Inlet sands extend up-dip into flood-tidal delta sandbodies that average 4 m in thickness and pinch out in lagoonal muds. Although showing much greater lateral continuity than the other reservoir units, the upper shoreface sandstones do not exhibit biomoldic porosity and are a less productive unit. Such an understanding of the architecture of the various reservoir components present in a barrier island shoreline system is essential when planning a secondary recovery program.

• OSTI ID: 7079428
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALBERTA
CANADA
DEVELOPED COUNTRIES
ENHANCED RECOVERY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOLOGY
GEOMETRY
MAPPING
MATHEMATICS
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
PLANNING
RESERVOIR ROCK
RESOURCES
STIMULATION
STRATIGRAPHY
TRIASSIC PERIOD
WELL STIMULATION